Telegraph signal enciphering key tape producing device



Aug. 20, 1946. B. syswlzzzY -2;406; 046

TELEGRAPH SIGNAL ENCIPHERING KEY TAPE PRODUCING DEVICE Fil ed May 21, 1942 AAA /4 i INVENTOR B. 5. SWEZEY ATTORNEY Patented Aug. 20, 1946 TELEGRAPH SIGNAL ENCIPHERING KEY TAPE PRODUCINGDEVICE Bucdette S..Swezey, FloralPa'rk; N. Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N ..Y.., a corporation of New York Application May 21, 1942, Serial No. 443,908

8 vClaims.

'T This inventionrelates to secret telegraph trans- "mission systems. Moreparticularly, this invention relates to the preparation of key tape foriuse in enciphering andcleciphering permutationcode telegraph signals.

It isat times important that telegraph signals transmitted over telegraph lines be enciphere'd to: prevent the disclosure of confidential messages to unauthorized parties. One system which is probably most satisfactorily used at presentin enciphering Baudot code telegraph signals involves the use of what is known in the artas a key tape. Frequently more than one key tape willrb-e employed in enciphering and deciphering. .As thenumber of teletypewrlter stations is increased and as the need for secrecy becomes more important it is necessary to provide a larger number of key tapes. It is desirableto produce such tapes automatically. Preferably, the system of producing tapes should be. completel automatic and should not require any manual manipulation. It is an object of this invention to produce random key tapes entirely automatically. by means of comparatively inexpensiveequipment.

Reference is made to D, B, Perry Patent 2365,120, December 2,.1941 which discloses an arrangement wherein a group of polar relays; one corresponding .to .each .signal element of the .Baudot codesignals to'be enciphered are arranged to vlbratepeach at audifierentspeed. Periodicallysa key is operated manually. Depen'dentupon theposition assumed by the various relayarma- "tures associated with the' relays at the moment when thekey is operated, positions corresponding to the relays in a key tape will be punchedor remain .unpunched. The invention herein'repre- 1 sents an improvement over the arrangement dis closed in Patent 2,265,120 in that the manual operation of a. key is unnecessary. The circuit is entirely automatic.

The invention may be better understood from the following description when read with reference to the single figure of the drawing which shows an entirely automatic arrangement for controlling the perforation of a key tape by a group of vibrating relays.

Refer' now to the drawing. Five vibrating relays, numbered I to 5, control the operation of fivepunch-selecting magnets, numbered 1 t II.

Vibrating relay 6 controls the operation of punch- 2 position prior to the start of operations and varied from time to timea desired by means of their respective sliding switches I9,2I,26, 34, and.

The rates of vibration of the difierent relays are also changed automatically as the relays vibrate by changing the impedance of the path through the winding of each rela in response to the operation of other'relays. From time to time,'at random intervals, relay No. 6 operates. Dependent upon the positionsof the right-hand armatures associated with'relays I to 5, magnet -1 to I I" will be energized or deenergized and the corresponding perforating punches'not shown, will be selected or remain unselected in a well-known manner. When the armature of relay 6 engages its left-hand contact, punching magnet will be energized and the tapewill be punched in positions where the punches have beenselected.

The circuit will now be described in detail. It will be assumed that all of the armatures associated withwelays I to 5' are in the position indicated. A circuit may be traced from battery I3 through resistance I4, contact I5, windin of rela '2, variable resistance 20, sliding contact 2| and resistance 22 to-ground51, energizing wind- -ing 2. Contacts-4| and35 are opened. Contact '42 is closed.

A circuit maybe traced from battery I3 through resistance I4, contact 43, windin of relay 3, variable inductance 23 and sliding contact 24 to 'ground 51 energizing relay 3.

Contacts and 31 are closed. Contacts -43-and 38 are opened. A'circuit' may also be traced from batter I3 throughresistance I4,contact 45, winding of relay 4, variable resistance 25, sliding contact 26, 'contact 38,which shunts resistance 21 and condenser 28 connected in parallel with resistance 21,

'toground 51 energizing the winding of relay 4. Contacts and are closed and contact 45 is opened.

A circuit may be traced from battery I3 through resistance I4, contact 41, winding of relay 5, in-

ductance 29 and contact 35, which shunts inductance 30, to ground 51. Contact 48 is closed and contacts 41 and 40 are open.

A circuit may be traced from battery I3 through resistance I4, contact 49, winding of relay 6, contact 40, which shunts resistance 3|, inductance 3 32, variable resistance 33 and sliding contact 34 to ground 51 energizing relay 6. Contact 50 is closed and contact 49 is opened.

When the right-hand armatures of relays I to 6, inclusive, engage their respective left-hand contacts I6, 42, 44, 46, 48, and 50 parallel circuits are established from battery I3 through resistance I4, through the respective left-hand contacts of relays I to B, through resistances 5| to 56, through the windings of punch-selecting magnets 'I to II to ground 58. Each of the right-hand armatures of relays I to 5 which is in engagement I with its left-hand contact when the armature of relay 6 engages its left-hand contact 50 will close its respective circuit through its punch-selecting magnet and when magnet I2 is energized the corresponding selected punches will be operated to punch the tape in corresponding positions in a well-known manner.

The opening of the right-hand contacts associated with the right-hand armatures of relays I to 6 deenergize the windings of relays I to II. The armatures are restored to reengage their right-hand contacts. Then the operation is repeated.

Attention is particularly directed to the fact that as the left-hand armatures of relays l to i are attracted and released they vary the energizing paths of other relays of the group. This changes the rate of vibration of the armatures oi the various relays. In the case of relay I, the opening of contact 35 removes a shunt from around inductance 30. This will effect a momentary change in the rate at which the armature of relay 5 vibrates. The operation of relay 2, by opening contact 36, inserts resistance I! in series with the winding of relay I. This effects a change in the speed of operation of relay I. The operation oi relay 3, by opening contact 38, removes a. short circuit from around resistance 21 and condenser 28 which are connected in parallel. This effects a change in the rate of vibration of the armature of relay 4. By the closing of contact 31 of relay 3, resistance 22 is short-circuited momentarily causing a variation in the current of relay 2 and an irregularity in its rate of vibration. The operation of relay 4, by closing contact 39, connects a short circuit around inductance 32. This effects a change in the rate of vibration of the armature of relay Ii.

The operation of relay 5, by opening contact 40, removes a short circuit around resistance SI. This likewise eflects the rate of operation of relay 6. Sliding contacts I9, 2|, 24, 26, and 34 may be adjusted manually to vary the amount of resistance or inductance of the apparatus unit with which each is associated. This will provid an additional adjustment in the rate of vibration of each of the associated relays.

It will be realized that proper adjustments may b required so that magnets I to I2 will be fast enough to follow their respective relays I to 6 and fully perform their operations. Also relay I5 and magnet I2 should be slow enough to allow changes in the punch selections to take place (where such changes are being called for by the vibrating relays) between successive operations of the punching magnet I2.

It is pointed out, that even though a definite arrangement of circuit elements is shown as being established by the left-hand armatures o1 relays I to 8, the actual arrangement employed may be any desired combination of apparatus units. Also where a single armature or a make or a break contact is shown, the arrangement may provide for more than one armature and for front and back contacts each controlling the disposition of additional circuit elements which may be momentarily connected into or removed from the circuits, to further complicate the erratio vibrating action of th relays I to 5 for setting up a random selection, and to cause relay 6 to vibrate in an erratic manner to cause perora ins of the tape by magnet I2 in a random manner.

The manner in which the punched tape is advanced after it has been punched is well known in the art.

What is claimed is:

1. In a mechanism applicable for enciphering multielement permutation code telegraph signals, a group or vibrating relays for determining the individual marking and spacing elements in the multielement cipher code and a single vibrating relay for automatically controlling the registering of the elements determined by said group.

2. A mechanism in accordance with claim 1 in which the rate of vibration of the vibrating relays is varied in response to the vibration of said relays.

3. In a mechanism applicable for enciphering multielement permutation code telegraph signals, a vibrating relay. automatic means for varying the frequency of operation of said relay, and means dependent upon the operation of said relay for energizing a punch magnet.

4. In a mechanism applicable for enciphering multielement permutation code telegraph signals, a vibrating relay and a tape punching magnet controlled by said relay.

5. In a mechanism applicable for enciphering multielement permutation code telegraph signals, a relay conditioned to vibrate automatically to determine the nature of a particular signal element in the cipher code, and means connected to said relay for automatically varying the period of vibration of said relay.

6. In a mechanism applicable for enciphering multielement permutation code telegraph signals, a plurality of vibrating relays for determining the character of signal elements in an enciphering code, and means responsive to the operation of certain of said relays for varying the frequency of vibration of others of said relays.

7. .An electromechanical mechanism for producing enciphering key tape for permutation code telegraph signals comp-rising a plurality of relays having means for mutually varying their rate of operation automatically, and means connected to each of said relays for controlling an individual signal element recording device.

8. In a mechanism for producing enciphering key tape for permutation code telegraph signals, a plurality of relays arranged to vibrate at different rates, each relative to the other, and means responsive to the operation of said relays for varying the rate of vibration of said relays.

BURDE'I'IE S. SWEZEY. 

